Cnidaria is a phylum within Kingdom Animalia which consists of hydras, jellies (or jellyfish), sea anemones, and corals. All cnidarians are radially symmetrical, and there are two main radially symmetrical body types.
The stock market crash, on black Tuesday (October 29, 1929) began the Great Depression.
The prelude to the Great Depression was an economic bubble in the United States, caused by years of prosperity and inflated confidence. The 1920s had been a boom decade for American companies, which tallied up record production figures, skyrocketing sales and millions of dollars profit.